diff --git a/flake.nix b/flake.nix
index 9417a79b56..1d5fff0da0 100644
--- a/flake.nix
+++ b/flake.nix
@@ -50,6 +50,7 @@
             # These dependencies are required for building tinygo (go install).
             go
             llvmPackages_18.llvm
+            llvmPackages_18.llvm.dev
             llvmPackages_18.libclang
             # Additional dependencies needed at runtime, for building and/or
             # flashing.